Each human is a microbial laboratory, harboring an ecosystem of microbes whose numbers are greater than the total number of human cells in the body. In fact, for every one human cell there are approximately 10 microbial cells. The collective genome of the microbes living within each human is at least 150 times larger than the genome of the human that they inhabit.
The first phase of the Human Microbiome Project, under the auspices of the National Institutes of Health, was completed in 2012. This multimillion-dollar research program was funded to catalogue and better define the microbes that inhabit the living human. Significant findings from this research include: 1) the microbiome is not the same among all humans, but varies dramatically from one individual to the next. 2) The microbiome of the individual also can change quickly over time, depending on the circumstances of the individual (diet, environment, drugs, etc.). 3) The largest number of microbes in the human inhabit the gastrointestinal tract. Further, the highest concentration of these microbes is found in the large intestines. 4) The large intestines can be described as a digestion chamber for the human. In this area, the microbiome of organisms, mainly utilizing anaerobic (needing no oxygen) bacteria, break down the foods for either absorption or elimination. 5) The composition of each individual's microbiome is closely linked to that person's immune function. 6) In addition to a healthy microbiome promoting health, this ‘healthy’ microbiome appears to be essential for cultivating a growth or a ‘farm’ of human friendly microbes that sustain health.
Thus, the human gastrointestinal tract has trillions of microbes that are living in the intestinal track from the mouth to the rectum and appear to play a major role in the health and disease of each individual. Microflora is going to revolutionize our understanding of health and disease. For example, research has shown in human and animal models that those who have an elevated body mass index in the obese range and/or who have type 2 diabetes appear to have a different bacterial milieu than those without these conditions. In fact, when the microbiota from obese humans or animals are transferred to healthy animals of average weight, but devoid of bacteria of their own, these recipient animals appear to have a greater risk of eventually becoming obese or diabetic. In addition, rheumatoid arthritis, muscular dystrophy, multiple sclerosis, depression, fibromyalgia, and possibly some cancers may be linked to an altered or unfavorable microbiome. However, one of the major issues is how to populate humans with a microbiome that may be able to support or restore health. This is a medical issue that has been challenging.
To date, the three major ways of delivering ‘healthy’ or desirable bacteria to the human in an attempt to promote health are:
1. Through food and drinks. Many products such as prebiotics and probiotics are currently marketed with this claim. Probiotics are found in foods such as certain yogurts and kefirs, while prebiotics are found in whole grains, bananas, onions, garlic, honey and artichokes. In addition, probiotics and prebiotics are added to some foods and available as dietary supplement. In addition, everyday foods such as miso, sauerkraut, pickles, kimchi, Kombucha tea and other fermented foods may contribute to promote a healthy intestinal microbiome.
2. Through capsules and tablets that are taken by mouth and contain these organisms known as probiotics. Some brands are available with live bacteria. Most commercial brands suggest they have a range of million to billions of bacteria strains because the delivery system breaks down so much of bacteria through the gastric acids in our stomachs. The amounts delivered are actually unknown. Each of the foregoing methods lacks the ability to directly deliver bacteria to the rectal area or the vaginal area. Studies have suggested that bacteria or probiotics may impact the function of colonizing microbes. Other studies suggest that supplementing bacteria via probiotics may promote homeostasis of the gut microbiota rather than change its composition. Each of the foregoing methods lacks the ability to directly deliver bacteria to the rectal area or the vaginal area. Studies have suggested that bacteria or probiotics may impact the function of colonizing microbes. Other studies suggest that supplementing bacteria via probiotics may promote homeostasis of the gut microbiota rather than change its composition.
3. Through fecal microbiota transplant (FMT), the process of transplantation of fecal bacteria matched from a healthy individual into an unhealthy recipient. FMT involves restoration of the colonic microflora by introducing healthy bacterial flora through infusion of donor stool, e.g. by enema, orogastric tube, by mouth, or by other implantation means, in the form of a capsule containing freeze-dried material, obtained from a healthy donor. Previous terms for the procedure include fecal bacteriotherapy, fecal transfusion, fecal transplant, stool transplant, fecal enema, and human probiotic infusion (HPI). Because the procedure involves the complete restoration of the entire fecal microbiota, not just a single agent or combination of agents, these terms have now been replaced by the new term fecal microbiota transplantation. However, current procedures at best provide stool samples with an approximate match for the microbiome needs of a patient.
There remains a need for a personalized medicine approach to maintaining a healthy microbiome for individual patients.